Insulin resistance at different stages of diabetic kidney disease in India

Many studies showed that Insulin resistance (IR) is present in chronic renal failure and evidences suggest that IR can also occur in early stages of renal disease. There is paucity of data from India, hence this study was planned to assess the degree of Insulin resistance at different stages of diabetic nephropathy.

This is a cross sectional study with a total of 128 subjects (M: F; 81:47) divided into 3 groups based on their renal function, Group 1 (control) n=32, group 2 (Normoalbuminuria) n=26, group 3 (Microalbuminuria) n=59 and group 4 (Macroalbuminuria) n=43. Subjects on insulin treatment were excluded. Insulin was estimated by chemiluminescence method. Biochemical investigations were done by enzymatic procedures. Insulin resistance was calculated using HOMA method. The normal cut off value for HOMA IR (2.4) was derived using mean+2SD of control group.

There was no significant difference between the study groups with respect to age, BMI, duration of diabetes and glycemic control. Mean HOMA IR increased significantly with decreasing renal function (control: 1.30 +/- 0.53; Normo: 4.0 +/- 2.7; Micro: 5.8 +/- 4.1; Macro: 7.9 +/- 5.1, p < 0.0001). Larger percentage of subjects had HOMA IR (> or = 2.4) at different stages of diabetic kidney disease (Normoalb: 57.6%; Microalb: 76.2%, Macroalb: 90.6%) compared to normal (3.1%). The results of multiple logistic regression analysis showed an association between HOMA IR and diabetic nephropathy.

This cross-sectional study demonstrated an association between IR and diabetic kidney disease in Indian population with type 2 diabetes. Further prospective studies are needed to look for causative relationship between IR and renal function.